[Bug target/50176] [4.7 Regression] 4.7 generates spill-fill dealing with char-int conversion
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50176 Igor Zamyatin izamyatin at gmail dot com changed: What|Removed |Added CC||vmakarov at redhat dot com --- Comment #8 from Igor Zamyatin izamyatin at gmail dot com 2011-09-16 14:35:34 UTC --- I was checking coalescing part in IRA but it looks like coalescing is fine. Adding Vladimir, maybe he could give some advice here
[Bug target/50176] [4.7 Regression] 4.7 generates spill-fill dealing with char-int conversion
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50176
--- Comment #7 from Igor Zamyatin izamyatin at gmail dot com 2011-09-14
14:30:35 UTC ---
In RTL everythin is vice-versa, additional instruction appears:
For the bad case couple instructions are responsible for cb load (asmcons
dump):
(insn 52 51 53 5 (set (reg:QI 83 [ D.2685 ])
(mem:QI (plus:SI (reg/v/f:SI 75 [ inptr1 ])
(reg/v:SI 117 [ col ])) [0 MEM[base: inptr1_19, index:
col_90, offset: 0B]+0 S1 A8])) ../test_bad_4_6.c:42 66 {*movqi_internal}
(nil))
and later
(insn 62 61 122 5 (parallel [
(set (reg:SI 152 [ D.2685 ])
(zero_extend:SI (reg:QI 83 [ D.2685 ])))
(clobber (reg:CC 17 flags))
]) ../test_bad_4_6.c:47 123 {*zero_extendqisi2_movzbl_and}
(expr_list:REG_DEAD (reg:QI 83 [ D.2685 ])
(expr_list:REG_UNUSED (reg:CC 17 flags)
(nil
while in good case only one:
(insn 52 51 53 5 (parallel [
(set (reg/v:SI 84 [ cb ])
(zero_extend:SI (mem:QI (plus:SI (reg/v/f:SI 75 [ inptr1 ])
(reg/v:SI 119 [ col ])) [0 MEM[base: inptr1_19,
index: col_90, offset: 0B]+0 S1 A8])))
(clobber (reg:CC 17 flags))
]) ../test_good_4_6.c:42 123 {*zero_extendqisi2_movzbl_and}
(expr_list:REG_UNUSED (reg:CC 17 flags)
(nil)))
And life ranges in bad case became splitted:
a34(r152): [71..82]
a38(r83): [83..92]
And in good case only:
a34(r84): [71..90]
[Bug target/50176] [4.7 Regression] 4.7 generates spill-fill dealing with char-int conversion
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50176 --- Comment #5 from Igor Zamyatin izamyatin at gmail dot com 2011-08-29 11:48:12 UTC --- Yes, looks like this revision is the reason
[Bug target/50176] [4.7 Regression] 4.7 generates spill-fill dealing with char-int conversion
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50176 H.J. Lu hjl.tools at gmail dot com changed: What|Removed |Added Status|WAITING |NEW CC||rguenth at gcc dot gnu.org
[Bug target/50176] [4.7 Regression] 4.7 generates spill-fill dealing with char-int conversion
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50176 Richard Guenther rguenth at gcc dot gnu.org changed: What|Removed |Added Keywords||missed-optimization --- Comment #6 from Richard Guenther rguenth at gcc dot gnu.org 2011-08-29 13:50:56 UTC --- It performs perfectly sensible optimizations: @@ -91,11 +83,9 @@ y_33 = (int) D.2055_32; D.2056_34 = inptr1_19 + col_5; D.2057_35 = *D.2056_34; - cb_36 = (int) D.2057_35; D.2058_37 = inptr2_24 + col_5; D.2059_38 = *D.2058_37; - cr_39 = (int) D.2059_38; - cr.0_40 = (unsigned int) cr_39; + cr.0_40 = (unsigned int) D.2059_38; ... @@ -104,12 +94,11 @@ D.2066_48 = range_limit_47(D) + D.2065_46; D.2067_49 = *D.2066_48; *outptr_4 = D.2067_49; - D.2068_50 = outptr_4 + 1; - cb.1_51 = (unsigned int) cb_36; + cb.1_51 = (unsigned int) D.2057_35; D.2070_52 = cb.1_51 * 4; D.2071_54 = Cbgtab_53(D) + D.2070_52; D.2072_55 = *D.2071_54; - cr.0_56 = (unsigned int) cr_39; + cr.0_56 = (unsigned int) D.2059_38; D.2061_57 = cr.0_56 * 4; D.2073_59 = Crgtab_58(D) + D.2061_57; D.2074_60 = *D.2073_59; This seems to be at most a register allocation or target issue. What it does is change (unsinged)(int)*load to (unsigned)*load, eventually enlarging life-ranges (didn't double-check that).
[Bug target/50176] [4.7 Regression] 4.7 generates spill-fill dealing with char-int conversion
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50176 H.J. Lu hjl.tools at gmail dot com changed: What|Removed |Added Status|UNCONFIRMED |WAITING Last reconfirmed||2011-08-26 Ever Confirmed|0 |1 --- Comment #4 from H.J. Lu hjl.tools at gmail dot com 2011-08-26 21:42:10 UTC --- Can you verify if revision 173612: http://gcc.gnu.org/ml/gcc-cvs/2011-05/msg00390.html causes this regression?
[Bug target/50176] [4.7 Regression] 4.7 generates spill-fill dealing with char-int conversion
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50176 --- Comment #2 from Igor Zamyatin izamyatin at gmail dot com 2011-08-25 13:17:36 UTC --- For gcc with Target: x86_64-unknown-linux-gnu Configured with: ../configure --disable-bootstrap --enable-languages=c,c++ --prefix=/export/users/izamyati/gcc_4_6_2_prefix/ Thread model: posix gcc version 4.6.2 20110825 (prerelease) (GCC) everything is fine, no that spill-fill generated
[Bug target/50176] [4.7 Regression] 4.7 generates spill-fill dealing with char-int conversion
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50176 --- Comment #3 from H.J. Lu hjl.tools at gmail dot com 2011-08-25 13:56:52 UTC --- (In reply to comment #2) For gcc with Target: x86_64-unknown-linux-gnu Configured with: ../configure --disable-bootstrap --enable-languages=c,c++ --prefix=/export/users/izamyati/gcc_4_6_2_prefix/ Thread model: posix gcc version 4.6.2 20110825 (prerelease) (GCC) everything is fine, no that spill-fill generated Can we find which checkin caused this?
